I have a question, the fan club Happy days are listed three types of list of episodes,
http://www.fonzie.it/h_english.htm
I was very curious about the fan, I understand why some episodes have been put in different order but the others?

I would be curious to understand the logic that fans have used to their list of episodes, your opinion?

well, I think the link you posted for the International Happy Days Fan Site you posted explains it pretty well:

"One is the PRODUCTION ORDER: is the order that the episodes were made/produced.

The second is the ORIGINAL AIR DATE ORDER: is the order the episodes were originally aired on ABC"

then of course they have their own, "The Fan Club Order", which seems to be the production order with a few small changes; basically they adopt the air date order at the beginning and end of the seasons where it makes sense to and a few random episode order swaps, presumably to correct problems where the other orders don't make sense, like showing episodes at the old Arnold's after it has already burned down and such.

I personally don't care what order they show them in :D

you'd understand this but the others? for example, put pots on his own before it's not Broadway rather than later, as in other lists?